Enhanced Carbon Nanotube Ultracapacitors

The mission of this proposed research is to develop ultracapacitors (also known as electrochemical or supercapacitors) to address an array of military applications. These applications include pulsed power for directed-energy and kinetic-energy weapons, sensors, and power supplies and control systems for aircraft and spacecraft. The proposed innovation employs carbon nanotubes (CNTs) coated with pseudo-capacitive MnO2 material as nano-composite electrodes and ionic electrolyte for the construction of ultracapacitors. This novel approach, using nano-structured CNTs architectures, provides a high surface area of attachment for MnO2 nano-particles to maximize the charge efficiency and the power capacity and to reduce the series resistance. Preliminary results at Vanderbilt University, using CNTs/MnO2 nano-composite as electrodes of an ultracapacitor, has demonstrated enhanced capacitance of >400× over pristine CNT electrodes. The fine tailoring of the nano-scale attachment of the electrode material will ultimately result in optimal energy, power, and cycling capabilities, all of which will meet or exceed the required device performance. BENEFIT: Potential USAF Applications USAF applications of ultracapacitors include pulsed power for directed-energy and kinetic-energy weapons, sensors, and power supplies and control systems for aircraft and spacecraft. Ultracapacitors possess much higher energy density than conventional capacitors, and their power density is far superior to that of batteries including fuel cells, resulting in enhanced efficiency and space and weight savings, which will benefit each of the above applications. We note that most of these applications have missions in all branches of the military. Potential Commercial and other non-USAF Applications Minimizing the use of oil in the US economy requires the invention of advanced energy storage devices that provide orders of magnitude higher efficiencies over present commercial technology. The application of enhanced CNT ultracapacitors in the automotive, aviation, and military represents an enormous market, in which costs will be driven down and innovation will penetrate industries that might not otherwise pursue cutting edge science and engineering due to the inherent risk (and cost) associated with it. With respect to application in other Government agencies, Enhanced CNT ultracapacitors will have particularly dramatic effects on NASA applications. The potential enhancements over current technology will allow MgO2 enhanced CNT ultracapacitors to be utilized anywhere independent power sources are required. Ultracapacitors combined with battery technology can power spacecraft, lunar surface mobility systems, and portable electronic equipment.